Magnetic compass



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Patented Mar. 5, 1946 r UNITED 1ST-Ares i PATENTMZ. OFFICE *a i ivrAGNE'ilo ooi/miss Burl E. Sherrill, Peru, Ind.

continuation of application sen-MNO. 437,721, May 20, 1943. This application A pril 14, 1944,

Serial N o. 531,058

3 claims. (ci. 334.33)

, t This invention relates to certain novel improvements in magnetic compasses and more specifically to a simple and 'expeditious arrangement of Vparts for mounting the compass bowl within the compass housing whereby the same may be adjusted to assure proper compass directions, and

yhasfor its principal object theV provision of `an improvedv construction ofk this character whichY will be highly efficient in use and 'economical in manufacture.

Amongthe salient objects of this invention is the provision f a magnetic compass having a of a slot I6 formed lin the intermediate portion I3. Depending from this bottom wallrI4 is the post I9 which supports the lquadrantal Ycoiuec- Y tors I9", shown and 'described Ain my pending compass bowl adjustably mounted'within a comerence to the accompanying drawing showing the preferred form of construction, and in which:

Fig. 1 is a front elevational view of the compass embodied in my invention;

Fig. 2 is a reverse side part sectional elevational view of the same;

t Fig. 3 is a fragmentary elevational view taken substantially on line 3-3 of Fig. 2.

The present invention constitutes a continuation of that shown in my pending application, Serial No. 487,721, led May 20, 1943, for Letters Patent on a Magnetic compass, which became Patent No. 2,375,329, issued May 8,1945.

The drawing of this present applicationshows the preferred form of construction by which the several objects of my invention are accomplished. Only so much of the magnetic compass has been shown and will be hereinafter described, as is necessary for Van understanding of the new features of this present invention.

In this connection the magnetic compass includes a housing I0 on the top of which is mounted a screw cap II enclosing a compensator unit (not shown). The upper'or head assembly I2 of the compass contains other compensator mechanism (not-shown). The intermediate portion I3 [of the housing II! is substantially cylindrical in key section I5 which'ts yinto the-lower region application hereinbefore referred to.

Extending below this wall I4 is a sliirting" rah#- beted as at 20 to receive the edge 2| of a rotatable base 22 having an indicating ring 23, the base 22 serving as an enclosure for the quadrantal correctors and being carried bythe post I9 'andjatr tached thereto through and by the medium of a n'ger knob 24. Y

Formed in the, intermediate portion I3 of the housing` ID opposite theelongated slot I6 is a sight opening orwindow 25'. My improved compass bowl is indicated at 26 and comprises'a cylindrical' body 21" of vtransparent material u"and a cap or upper section 28 serving as an expander to compensate for expansion of the uid within the compass bowl 26. This upper section 28 is of a smaller diameter than the compass bowl 26 andk projects into the head portion I2 of the housing I0. the bottom wall I4. It contains the compass rose or card 29 similar in 'construction to that disclosed in my pending application hereinbefore referred to. Confined within and supported from the compassV bowland adapted to be properly positioned within the sight opening or window 25 is a lubber 1ine'30. This lubber line 30 is so properly positioned by manually adjusting the compass bowl 26. This is accomplished by associating with the compass bowl in a fixed position with respect thereto, a threaded screw element 3l. The exterior end of this screw element 3| projects through the elongated slot I6 and has threaded thereon a thumb nut 32. of the iinger button 32 upon the screw element 3|, the nger button 32 may be brought away from contact with the wall of the intermediate portion I3, and in this position of the thumb nut 32 the compass bowl may be adjusted relative to the intermediate portion VI3 to properly position the lubber line within the sight opening or window 25.V After this adjustmentY has beenv made, the thumb nut 32 is screwed upon the screw element 3| into bearing engagement with the adjacent wall 33 of the intermediate portion I3, thus securing the compass bowl in its proper fixed adjusted position.

Under normal conditions, the lubber line 30 is disposed centrally. with respect to a vertical axis through the sight opening or window 25 and the indicating plate 34 adjustably mounted on the'front face Vof the intermediate portion I3 The compass bowl 26 rests upon By rotation by a pair of screw elements 35 which pass through a horizontal slot 3B formed in the plate 34. Both the plate and the compass bowl may be adjusted so as to bring about their proper position with respect to the sight opening or window 25.

To assemble the compass bowl within the compass housing the operator rst unscrews the knob 24 from the post I9. This will permit removal of the base 22.` Next theV operator removes the screws l5', which permits the removal of the bottom wall I 4 of the intermediate portion I3. Then,

by loosening the thumb nut 32, the entire com-v pass bowl and rose, together with the lubber line, may be removed from within the compass housing I0. Thus, it is apparent that this simplicity of parts results in convenient and. vexpeditious assembly.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation andv modication without 'departing from the spirit of the invention.L I therefore do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of such variations and modifications as come within the scopeof the appended claims.r

Having thus described my invention, what I claim as new and. desire to prqtect by Letters Patent is:

1, A. compass comprising an intermediate housing portion having a removable bottom wall, means for removably connecting the bottom wall tol the intermediate portion, said intermediate portion providing an elongated slot, a compass bowl arranged in said intermediate portion upon said bottom wall, a thread-bearing element carried by said. compass. bowl and movable in said elongated slot, a thumb nut having threaded engagement with said thread bearing element and adapted when in a predetermined position to h'ave clamping engagement with the adjacent wall of said intermediate portion to iix said compass bowl in an adjusted position within said intermediate portion.

2. A compass comprising an intermediate housing portion of cylindrical 'formation in cross section and having a sight opening4 formed on one side thereof and an elongated slot formed in an opposite side, a compass bowl within said intermediate portion, means supporting said compass bowl 'within said intermediate portion, a thread bearingimember carried by the compass bowl and movable in said elongated slot, a thumb nut threaded upon said thread bearing member and adapted to have bearing engagement with an adjacent wall of the intermediate portion for releasably connecting said compass bowl in a xed position within said intermediate4 portion..

3.. A magnetic compass comprising a body portion providing. a compass bowl chamber and having a. wall portion provided with an elongated slot,v a compass howl mounted in saidv chamber,` a bottom wall4 for saidchamber and supporting said compass bowl for rotation withinv said chamber and having a key portion engageablev in said slot to hold said bottom wall against rotation relative to said compass bowl, a threaded member carried by the compass bowl and movable. in said slot, and a thumb nut threaded on said threaded member and adapted' torhave clamping engagement with said wall to releasably x said com. pass bowl in .a fixed position within said cham. ber.

BURL E. SHERRILL. 

